Blow-out roof for electrostatic dust separator



Jan. 16, 1968 G. WENDEL ET AL 3,363,376

BLOW-OUT ROOF FOR ELECTROSTATIC DUST SEPARATOR Filed Jan. 23, 1967 INVENTORS Gz'mter Wendel Horst Blazer BY g dag pi ATTORNFYS United States Patent 3,363,376 BLOW-OUT ROOF FOR ELECTROSTATIC DUST SEPARATOR Gunter Wendel and Horst Blaer, Frankfurt am Main,

Germany, assignors to Metallgesellschaft Aktiengesellschaft, Frankfurt am Main, Germany Filed Jan. 23, 1967, Ser. No. 610,866 Claims priority, application Germany, Feb. 9, 1966, M 68,324 3 Claims. (Cl. 52-262) ABSTRACT OF THE DISCLOSURE The roof of an electrostatic dust separator is composed of concrete planks covered by metal sheets which are capable of being separated from the side walls and roof beams of the separator to release the gas pressure of an explosion in the separator.

Constructions for an electrostatic dust separator made of steel in which the roof acts as a relief valve for the gas pressures produced when an explosion occurs in the separator are known. The side edges of the roof are releasably pressed against the roof beams and walls of the separator.

This invention is directed to the construction of a concrete roof for a concrete separator which will also act as a relief valve for the interior pressures created by an explosion in the separator. In general, the roof is composed of a lower layer of lightweight concrete planks extending between the walls and the roof beams, a metal cover layer on the lower layer of planks, joints between the metal cover layer and the walls and roof beams which are releasable from the walls and roof beams by the pressure of an explosion in the separator, a layer of heat insulating material on the metal cover layer, and an upper layer of lightweight concrete planks on the insulating material.

In this invention, the metal cover layer is composed of individual metal sheets, the edges of which are pressed by angle irons and channel irons against seals on the walls and roof beams, respectively. Further roof rafters extend between the roof beams and side walls to give additional support to the lower layer of cement planks and channel irons weighted down with heavyweight concrete are used to hold the edges of the metal cover sheets on the rafters.

This construction has the same advantage as in the known construction in that the entire roof is used as a relief valve for explosive pressures occurring within the separator. Moreover, this advantage is more important for concrete electrostatic separators than for steel electrostatic separators. Conventionally, the roofs for concrete separators are heavy and rigid. In contrast thereto, the roof of this invention is soft and light, but strong enough to withstand greater than and less than atmospheric pressures. The roof is easily installed and replaced.

The means by which the objects of the invention are obtained are described more fully with reference to the accompanying drawings in which:

FIGURE 1 is a cross-sectional view through the roof of this invention;

FIGURE 2 is a cross-sectional view taken on the line 22 of FIGURE 1;

FIGURE 3 shows an enlarged detailed cross-sectional view of the joint between the roof and the side wall of the separator;

FIGURE 4 is a similar view of the joint between the roof and a roof beam;

FIGURE 5 is a similar view of the joint between the roof and a rafter; and

3,363,375 Patented Jan. 16, 1968 FIGURE 6 is a similar view showing the joint between the metal roof sheets extending transversely of a rafter.

The roof 1 of a concrete electrostatic dust precipitator is composed of concrete rafters 2 supporting a lower layer of lightweight concrete planks 3 and an upper layer of concrete planks 3a and between which is a layer of heat insulating material 4. These planks form two layers extending between the roof beams 5 and the outer walls 6. On top of the lower layer of concrete planks 3 is a metal covering composed of individual metal sheets 7 which is used as a gas-tight seal and for forming the joints. It therefore functions both to hold the lower layer of concrete planks and at the same time form a gas-tight cover for the roof. The joints are shown in detail in FIGURES 3 to 6.

In FIGURE 3, the roof is secured to the outside wall 6 by means of angle irons 8 slidably bearing on the edges of the roof sheets 7. The vertical flange of angle iron 8 is pressed against a sealing strip '9 and fastened to the wall 6 by means of screws 10. The horizontal flange 8a of the angle iron presses down on a sealing strip 11 which rests on the lower layer concrete planks 3 and extends over and bears down on the edge portion of sheet 7. Thus sheet 7 can he slid out of the joint.

FIGURE 4 shows the joint between the roof and the roof beams 5. Again, an angle iron 8 is secured through a sealing strip 9 to the roof beam by means of screws 10. As in FIGURE 3, the horizontal flange of the angle iron bears both on a sealing strip 11 and on roof sheet 7 which bears on the concrete planks 3.

FIGURE 5 shows the joint between the metal sheets 7 and a rafter 2. A channel iron 12 weighted by a heavy concrete member 13, while also supporting the upper layer of concrete planks 3a, bears down on sealing strips 14 and extends over the edge portions of the metal sheets 7. This produces a gastight seal and a joint which can be loosened by an explosion.

FIGURE 6 shows the joint between the metal sheets where the joint extends transversely of the rafter 2. This construction is essentially the same as shown in FIG- URE 5 as the channel iron 12 weighted by the concrete 13' presses on seals 14 and on the edge portions of the sheets 7.

When an explosion occurs in the separator, the pressure wave travels toward the roof. When hit by the pressure wave, the lower layer concrete planks 3 are pushed upwardly against the metal sheets 7 since they are freely resting on the side walls, roof beams and rafters. The individual metal sheets 7 are thus bent and pull out from the sealing strips 11 and/or 14 so that the joint is open. Thus the roof opens as a safety valve for the release of the pressure wave. The concrete plank layers 3 and 3a, together with the metal sheets, are all lifted so that the electrostatic dust separator in its entirety is saved from dam-age to a considerable extent.

Having now described the means by which the objects of the invention are obtained, we claim:

1. In an electrostatic dust separator, a concrete roof construction for the relief of gas pressures caused by an explosion in the separator and for protecting the walls and inner parts of the separator from damage comprising roof beams extending between said walls, a lower layer of lightweight concrete planks supported on said walls and roof beams, a metal cover layer on said lower layer planks, joint means holding said metal cover layer to the walls and roof beams and being releasable therefrom by the pressure of an explosion in the separator, a layer of heat insulating material on said metal cover layer, and an upper layer of lightwight concrete planks on said insulating material.

2. In a separator as in claim 1, said metal cover layer further comprising a plurality of metal sheets, and said -joint means including angle irons joined to the ends of said sheets, and clamping means for releasably holding said angle irons to said walls and roof beams.

3. In a separator as in claim 2, further comprising rafter means between said walls and roof beams for further supporting said lower layer of concrete planks and said metal sheets, sealing means on the edges of the metal sheets, a channel iron on said sealing means, and weight means on said sealing means for pressing said channel iron down upon said metal sheets and holding said sheets during normal operation of the separator.

References Cited UNITED STATES PATENTS 3,258,887 7/1966 Mostoller 52 9s 3,332,175 7/1967 Hawes et a1. 52-1 FOREIGN PATENTS 1,126,180 7/1956 France.

HENRY C. SUTHERLAND, Primary Examiner. 

